The failed thoracocentesis

How often do we consider a differential diagnosis of diaphragmatic hernia in cases of failed thoracocentesis? How many of us remember that omental fat in the chest can behave in a fluid manner, layering along the chest wall, resulting in the misinterpretation of a decubitus view. A case is presented of a diaphragmatic hernia that was missed on conventional chest radiographs resulting in CT having to be performed. A high degree of suspicion is mandatory to reach the final diagnosis. Radiographs could be used more effectively and CT avoided.